RE: [PATCH v4] ARM: perf: save/restore pmu registers in pm notifier

Sudeep，

-----Original Message-----
From: Sudeep Holla [mailto:sudeep.holla@arm.com]
Sent: 2014年5月14日 17:32
To: Neil Zhang; Will Deacon
Cc: Sudeep Holla; 'linux@arm.linux.org.uk';
'linux-arm-kernel@lists.infradead.org'; 'linux-kernel@vger.kernel.org';
'devicetree@vger.kernel.org'
Subject: Re: [PATCH v4] ARM: perf: save/restore pmu registers in pm notifier



On 14/05/14 03:28, Neil Zhang wrote:

quoted

quoted

-----Original Message-----
From: Will Deacon [mailto:will.deacon@arm.com]
Sent: 2014年5月14日 2:45
To: Neil Zhang
Cc: Sudeep Holla; 'linux@arm.linux.org.uk';
'linux-arm-kernel@lists.infradead.org';
'linux-kernel@vger.kernel.org'; 'devicetree@vger.kernel.org'
Subject: Re: [PATCH v4] ARM: perf: save/restore pmu registers in pm
notifier

On Mon, May 12, 2014 at 11:22:09AM +0100, Neil Zhang wrote:

quoted

quoted

quoted

The device tree bindings for power domains is under discussion [1]

Thanks for the information.
But it currently for device only, core related stuff are not supported.
And is it really good to register power provider for core and let
vfp / pmu etc to get it?

What's your suggestion about it?
Is it OK that I add it under the PMU node?

I don't really mind. I just want to avoid re-inventing the wheel in a
PMU-specific way and having to maintain that code forever because it
ended up in our DT description.

Will

I will prepare another patch to add DT description under PMU since
there is no generic power domain support for pm notifier if no other

concerns.

quoted

We can change the manner if there is generic power domain support for

pm notifier later.

quoted

Thanks.

No, please don't add any DT bindings for power domains specific to PMU
node.
We can't change the DT bindings once added.

As I pointed out the DT bindings for generic power domains are under
discussion.
See if you can reuse it, if not help in extending it so that it can be used.

Sorry for reply later.
As I said before the under discussed generic power domain is not suitable for
CPU peripherals since they are all known belong to CPU or cluster power domain.
If we want to follow the way they are discussion, we need to register core 
and cluster power provider, and need vfp/gic/pmu etc to require them.
Is it really suitable?

Regards,
Sudeep

Best Regards,
Neil Zhang
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